Suitable for cleaning and inspecting check valve with strainer for mixing faucets. The tip is wide and easy to use without scratching. The tip is wide at 0.7 inches (18 mm), so you can work without sinking the grooves of the rubbed screws. Used for cleaning and inspecting various large diameter screws and check valves with strainer for mixing faucets and cosmetic valves with checks. Ideal for cleaning and inspecting the strainer of mixing faucets.